The effect of diets with different protein levels on the growth of pink shrimp juveniles Penaeus notialis under laboratory conditions was studied. Animals with initial average weight of 0.4 g were fed during 56 days using four isocaloric
(350 kcal/100 g) and isolipidic (8.7 %) balanced diets, containing 30, 35, 40 and 45 % of protein. Shrimp fed with the diet containing 45 % of protein reached the highest growth and the best values for nutritional indixes under evaluation.
The protein efficiency tended to increase when the protein level in food also increased. A significant relationship was verified between shrimp weight and in vitro digestibility of diets. No relationship was detected between enzimatic
activity of trypsin and general proteases for the different levels of protein tested. The histological analysis of the hepatopancreas in shrimp fed with diet containing 30 % of protein showed degeneration and necrosis of the
hepatopancreatic tubes in contrast with the remaining treatments where the usual structure of the tissue was observed.